Or, perhaps the craziest idea of them all: Re-open the South-East Island aka the War Island. Doing so would provide a boost just from returning old players. Off the top of my head I can think of at least 3 or 4 people who would return to BM if word got out that they could play on SEI again, and they would probably start additional characters on other islands as well. I know Tom has said that the war islands didn't fit his idea of BattleMaster, but I can only say that almost anyone I know in the game on a personal level thinks closing them was a bad idea. Myself included.
+ OVER 9000
omg omg omg please please pleaaaaase bring back the war islands. It was one of the most fun things in the game, really...